1. Field of the Invention
This invention relates to development apparatus which use dry developer material or toner for developing latent images in such electrostatographic reproduction machines as copiers and printers. More particularly, the present invention relates to a device for sealing around an aperture (used in such development apparatus) for replenishing the developer material or toner as such material or toner is used up in image development.
2. Background Art
Development apparatus, which hold and use dry powdery developer material consisting of, or containing, toner particles at a desired concentration for developing latent images in electrostatographic reproduction machines, are well known. Because such image development ordinarily depletes or uses up toner particles, additional toner particles must frequently be added to the development apparatus in order to maintain their desired concentration. The higher the speed and volume of the host reproduction machine of the development apparatus, or the larger and more solid the toned image areas, the higher the toner depletion rate, and hence the greater the frequency of adding or replenishing toner particles to the development apparatus.
The adding or replenishing of dry, powdery toner particles as such, ordinarily can be a messy job. Therefore unique toner containers as disclosed for example in U.S. Pat. No. 4,972,887 ( '887 patent) have been disclosed in order to make the job less messy. The disclosed toner container therein includes a mouth with a flanged lip portion which cooperates with a toner receiving part of a development apparatus. The toner receiving part of the development apparatus includes a replenishment aperture through which toner from the container passes or drops into the development apparatus. To add or replenish toner to the development apparatus, the toner container is inverted and its flanged lip portion (while still closed) is positioned on the toner receiving part and slid in a forward direction to a (usually open) content-discharging position over the replenishment aperture. To remove the container from over the toner receiving or replenishment aperture, for example, after it is completely discharged, the flanged lip portion thereof is slid in a reverse direction away from the aperture.
In the '887 patent, in order to prevent toner spillage and leakage through areas between the lips of the toner container and the toner receiving part of the development apparatus, it is suggested generally that the surface area of the toner receiving part surrounding the toner receiving or replenishment aperture can be covered with a cloth, felt, fiber or other compressible material acting as a sealing device. Unfortunately, however, as the frequency of sliding the lip portion of a toner container back and forth increases in newer, high speed and high volume reproduction machines, the physical integrity of such a sealing device can quickly deteriorate leading to undesirable leaking of toner particles into open areas of the machines. Additionally, forces required for, and hence the difficulty of, sliding the container onto and away from the replenishment aperture become serious concerns.